Intravascular therapy is performed by using a high-function catheter such as a balloon catheter, a stent, or the like. An imaging apparatus for diagnosis such as an optical coherence tomography (OCT) apparatus, an intravascular ultrasound (IVUS) apparatus, and the like has been generally used in order to perform preoperative diagnosis or to check postoperative progress.
The optical coherence tomography apparatus has a built-in optical fiber, to a distal end of which an imaging core having an optical lens and an optical mirror is attached. At least a distal end portion of the optical coherence tomography apparatus has a transparent sheath.
Then, the sheath is inserted into a blood vessel of a patient. While the imaging core is rotated, light is emitted to a vascular wall via the optical mirror. The light reflected from the blood vessel is received again via the optical mirror, and radial scanning is performed, thereby configuring a cross-sectional image of the blood vessel, based on the obtained reflection light. Then, while the optical fiber is rotated, a pulling operation (generally called pulling-back) is performed at a predetermined speed, thereby forming a three-dimensional image of an inner wall in the longitudinal direction of the blood vessel (refer to JP-A-2007-267867). In addition, as an improved OCT type, a swept-source optical coherence tomography (SS-OCT) apparatus which uses a swept-source has also been developed.
In the intravascular ultrasound apparatus, a target to be emitted is ultrasound. That is, the ultrasound is emitted toward biological tissues, and reflected waves from each boundary surface of the biological tissues are detected so as to obtain information of the biological tissues in the emitting direction. The imaging core which emits and detects the ultrasound is rotated, thereby configuring an ultrasound cross-sectional image. Then, pulling-back is performed so as to form a three-dimensional image. Furthermore, a technique for generating a cross-sectional image and a three-dimensional image by applying both ultrasound and light has been known (refer to JP-A-11-56752).